Heart failure and congenital heart defects threaten the lives of several thousand children each year. The only FDA-approved long term pediatric heart support device is the Berlin Heart Excor, which is based on 30+ year old technology and is fraught with complications including blood clots forming in the device requiring frequent device replacement. The recipients of this technology are at high risk for strokes, bleeding, and infection and the pumps are driven by a large 220 lb. console, which limits patient mobility and prevents hospital discharge. In spite of these severe limitations, 90% of Excor recipients survive to transplant, although the median duration of support is only 35 days. A safer device would dramatically reduce the complications of support, permit discharge to home, and allow doctors to deploy the technology earlier, before a child reaches the brink of death. VADovations is developing a miniature implantable pump platform, the Revolution, in which minor modifications of 2 components can be implemented to adjust the pump performance to support the right or left side of the heart. The devices are 8 mm in diameter and 50 mm in length, about the size of a 'AAA' battery, compared to the market leading Heartmate II, which is 47 mm in maximum diameter and 95 mm in length, the size of a 'D' cell battery. Our adult Revolution RVAD can safely generate the lower blood rates needed for a pediatric left heart assist device and has demonstrated exceptionally low blood trauma in bench-top studies and during implants in sheep for durations up to one month with no long-term blood thinners. Building upon these promising results, we propose a Fast Track, combined Phase I/II SBIR to re-purpose the Revolution RVAD as a pediatric left heart assist device, the Revolution MINI, for children ages 1 and up. Then we will revise the design to create the Revolution NEO for neonates and infants, aged 0-1, who represent the largest clinical need for pediatric heart support. During Phase I, we will demonstrate the feasibility and efficacy of the MINI for pediatric blood flow rates and pressures during in vitro and short term animal experiments. In Phase II, we will conduct chronic animal implants to evaluate the long-term function, biocompatibility, and durability of the pumps and perform verification and validation studies of the Revolution MINI system to prepare for a US clinical trial. Throughout the program, we will focus considerable efforts on anatomic fit modeling and studies to devise approaches so that these devices can be implanted in the smaller bodies of children, to avoid pumps protruding from the body, as occurs with the paracorporeal Excor. Superior hemocompatibility, smaller size, and the ability to leverage adult system components, combine to produce pediatric heart assist devices that will offer fewer complications, permit patient discharge to home, and be economically viable to revolutionize the treatment of pediatric heart failure.